You can't replace the iPhone 11 with an A15 processor. iphone11 processor is a13, iPhone11 change 13 is to buy a imitate iPhone13 back cover, so it looks like iPhone13, of course, the front is still the original LCD screen, and iPhone13 oled display is qualitatively different, The processor is also impossible to match the Apple a15 processor of the iPhone13, and the performance of the 13 is completely beaten by the real 13.